QoS Deployment                                           Experiences                                        SANOG VII Mumb...
Agenda        What is QoS?        Why QoS?        Benefits of QoS For Service Provider        QoS Functional Components & ...
What is QoS?      “Collection of technologies which       allows applications/users to request       and receive predictab...
What is QoS? (cont…..)             Measure of transmission quality and service             availability of a network      ...
What is QoS? (cont…..)             Objectives of QoS               • Supporting dedicated bandwidth               • Improv...
Agenda        What is QoS?        Why QoS?        Benefits of QoS For Service Provider        QoS Functional Components & ...
Why QoS?             Technological Reasons               • Real time applications are sensitive to delay, jitter          ...
Agenda        What is QoS?        Why QoS?        Benefits of QoS For Service Provider        QoS Functional Components & ...
Benefits of QoS For Service                       Provider      • B/W Management         by congestion        management a...
Agenda        What is QoS?        Why QoS?        Benefits of QoS For Service Provider        QoS Functional Components & ...
QoS Functional Components                 & Models             QoS Functional Components               – Classification of...
QoS Functional Components               & Models (cont…..)             QoS Functional Components (cont…)               – M...
QoS Functional Components             & Models (cont…..)             QoS Models                     Best Effort           ...
QoS Functional Components               & Models (cont…..)                                        DiffServ – QoS Model    ...
QoS Functional Components               & Models (cont…..)      DiffServ – QoS Model             Per-Hop Behaviors (PHB)  ...
QoS Functional Components             & Models (cont…..)                      DiffServ – QoS Model (AF PHB)               ...
Agenda        What is QoS?        Why QoS?        Benefits of QoS For Service Provider        QoS Functional Components & ...
QoS in MPLS Network             MPLS support for QoS               – MPLS can support both IntServ and DiffServ           ...
QoS in MPLS Network                                    (cont…)       Co-existence of MPLS & DiffServ is scalable          ...
QoS in MPLS Network                                   (cont…)      MPLS & DiffServ      Label Header for Packet Media     ...
QoS in MPLS Network                                   (cont…)             DSCP & MPLS EXP Bits               – DSCP field ...
Agenda        What is QoS?        Why QoS?        Benefits of QoS For Service Provider        QoS Functional Components & ...
QoS Deployment Experiences                    QoS deployment in MPLS network      •      Step 1: Identifying application r...
QoS Deployment Experiences                (Cont….)      Step 1: Identifying Application Requirements      • Importance of ...
QoS Deployment Experiences                (Cont….)      Step 1: Identify Application Requirements (cont..) - QoS        Re...
QoS Deployment Experiences                (Cont….)      Step 2: Defining Policies      • Understanding network topology an...
QoS Deployment Experiences                (Cont….)      Step 2: Defining Policies (cont….) –      • Defining SP’s aggregat...
QoS Deployment Experiences                (Cont….)      Step 2: Defining Policies (cont….) –             Example: QoS Stan...
QoS Deployment Experiences                (Cont….)      Step 3: Testing Policies      • QoS policies function of customer ...
QoS Deployment Experiences                (Cont….)      Step 3: Testing Policies (cont….)      • Test QoS policies in the ...
QoS Deployment Experiences                (Cont….)      Step 3: Testing Policies (cont….)      • Test QoS policies in the ...
QoS Deployment Experiences                (Cont….)      Step 3: Testing Policies (cont….)      • Test QoS policies in the ...
QoS Deployment Experiences                (Cont….)      Step 4: Implementing Policies      •      Perform Classification o...
QoS Deployment Experiences                (Cont….)      Step 5: Monitoring and Adjusting      • Measure delay and loss for...
Thank YouReliance Proprietary and Confidential
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Shinde qos-mpls-tutorial

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Shinde qos-mpls-tutorial

  1. 1. QoS Deployment Experiences SANOG VII Mumbai, India 16-24Jan’06 Rajesh Shinde rajesh.shinde@relianceinfo.comReliance Proprietary and Confidential
  2. 2. Agenda What is QoS? Why QoS? Benefits of QoS For Service Provider QoS Functional Components & Models QoS in MPLS Network QoS Deployment ExperiencesReliance Proprietary and Confidential
  3. 3. What is QoS? “Collection of technologies which allows applications/users to request and receive predictable service levels in terms of data throughput capacity (bandwidth), latency variations (jitter) and delay"Reliance Proprietary and Confidential
  4. 4. What is QoS? (cont…..) Measure of transmission quality and service availability of a network Transmission quality of the network is determined by the following factors: Latency, Jitter, and Loss. QoS from User Perspective: The network capability to provide the desired application performance for Voice,Video,and Data! QoS from Service Provider Perspective: Methods to utilize existing network capacity efficiently and meet performance requirements and achieve the maximum traffic throughput. “Managed unfairness”Reliance Proprietary and Confidential
  5. 5. What is QoS? (cont…..) Objectives of QoS • Supporting dedicated bandwidth • Improving loss characteristics • Avoiding and managing n/w congestion • To give priority to certain mission critical applications in the n/w • To maximize the use of the current network investment in infrastructure • Better performance for delay sensitive applications such as Voice and Video • To respond to changes in n/w traffic flowsReliance Proprietary and Confidential
  6. 6. Agenda What is QoS? Why QoS? Benefits of QoS For Service Provider QoS Functional Components & Models QoS in MPLS Network QoS Deployment ExperiencesReliance Proprietary and Confidential
  7. 7. Why QoS? Technological Reasons • Real time applications are sensitive to delay, jitter and packet loss • Voice, Video, and Data application traffic demand varying service requirements • Over subscription of available bandwidth for multiple applications • Resultant congestion and ensuring of SLAs for priority traffic in networks • Optimization of bandwidth utilizationReliance Proprietary and Confidential
  8. 8. Agenda What is QoS? Why QoS? Benefits of QoS For Service Provider QoS Functional Components & Models QoS in MPLS Network QoS Deployment ExperiencesReliance Proprietary and Confidential
  9. 9. Benefits of QoS For Service Provider • B/W Management by congestion management and avoidance mechanism • Better handling of N/W capacity for new applications / services • Increase in revenue by selling multiple service classes over shared infrastructure like MPLS backbone • Predictive behavior guarantee on the data IP / MPLS network (which are usually best effort).Reliance Proprietary and Confidential
  10. 10. Agenda What is QoS? Why QoS? Benefits of QoS For Service Provider QoS Functional Components & Models QoS in MPLS Network QoS Deployment ExperiencesReliance Proprietary and Confidential
  11. 11. QoS Functional Components & Models QoS Functional Components – Classification of packets on the basis of Layer 2 parameters (802.1Q CoS bits) Layer 3 parameters (IP Precedence, DSCP, source MPLS EXP bits or destination IP ) Source port, destination port, or stateful inspection – Policing / Shaping Both identify the traffic rate violations similarly Policing-Dropping violating traffic or marking it with higher drop probability Shaping-Delays the excess traffic by using buffer & shapes the flow to configured rateReliance Proprietary and Confidential
  12. 12. QoS Functional Components & Models (cont…..) QoS Functional Components (cont…) – Marking / Rewriting Eases the classification in Service Provider’s Core n/w Carries packet’s service class & drop probability information Can be tied to policing Layer 2 and layer 3 specific (e.g. FR DE, ATM CLP, 802.1p/q, IP DSCP, IP Precedence, MPLS Experimental field) – Scheduling (Congestion Management/Avoidance) Congestion Management (Queuing- CBWFQ, LLQ, MDRR) • Creation of queues corresponding traffic classes • Managing the front end of queues by transmitting the packets from queues on the basis of priority & b/w share Congestion Avoidance (Dropping-With RED) • Monitoring network traffic loads to anticipate and avoid congestion at common network bottlenecks • Achieved by selective dropping of packets on the basis of drop probabilitiesReliance Proprietary and Confidential
  13. 13. QoS Functional Components & Models (cont…..) QoS Models Best Effort • Traditional IP service with no state (no traffic classification) InteServ (Integrated Service) – RFC 2210,2211,2212,2215 • First effort towards IP QoS • Signaled QoS with per flow state • Resource/policy admission control • Not scalable over internet DiffServ (Differentiated Service) – RFC 2274,2275 • Provisioned QoS • Per flow aggregate QoS • No scalability issue–Better choice for Service Provider • No resource/policy admission controlReliance Proprietary and Confidential
  14. 14. QoS Functional Components & Models (cont…..) DiffServ – QoS Model Ingress Interior Egress Node Node Node PHB TCB TCB PHB PHB Traffic Classification and Conditioning Per-Hop Behavior Classification/Marking/Policing Queuing/DroppingReliance Proprietary and Confidential
  15. 15. QoS Functional Components & Models (cont…..) DiffServ – QoS Model Per-Hop Behaviors (PHB) – Expedited Forwarding (EF): RFC2598 • Dedicated low delay queue • Comparable to Guaranteed B/W in IntServ – Assured Forwarding (AF): RFC2597 • 4 queues × 3 drop preferences • Comparable to Controlled Load in IntServ – Class Selector: Compatible with IP Precedence – Default (best effort)Reliance Proprietary and Confidential
  16. 16. QoS Functional Components & Models (cont…..) DiffServ – QoS Model (AF PHB) AF Class 1: 001dd0 AF Class 2: 010dd0 AF Class 3: 011dd0 AF Class 4: 100dd0 dd = drop preference Eg. AF12 = Class 1, Drop 2, thus “001100” • 4 independently-forwarded AF classes • Within each AF class, 3 levels of drop priority! This is very useful to protect conforming to a purchased, guarantee rate, while increasing chances of packets exceeding contracted rate being dropped if congestion is experienced in the core.Reliance Proprietary and Confidential
  17. 17. Agenda What is QoS? Why QoS? Benefits of QoS For Service Provider QoS Functional Components & Models QoS in MPLS Network QoS Deployment ExperiencesReliance Proprietary and Confidential
  18. 18. QoS in MPLS Network MPLS support for QoS – MPLS can support both IntServ and DiffServ – MPLS support for DiffServ being standardized (draft-ietf-mpls-diff-ext)Reliance Proprietary and Confidential
  19. 19. QoS in MPLS Network (cont…) Co-existence of MPLS & DiffServ is scalable 1000 flows MPLS: flows associated with FEC, mapped into DS: one label Scheduling/Dropping based on DSCP/MPLS MPLS: EXP bits DS: flows associated Switching with Class, mapped to based on DSCP LabelCo-existence of MPLS & Diff-Serv possible because of same scalability goals, both models do: - aggregation of traffic on Edge & processing of Aggregate only in Core Reliance Proprietary and Confidential
  20. 20. QoS in MPLS Network (cont…) MPLS & DiffServ Label Header for Packet Media Label 20 bits EXP Experimental Field, 3 bits S Bottom of Stack, 1 Bit TTL Time to Live, 8 Bits – Can be used over other layer-2 technologies – Contains all information needed at forwarding time – One 32-bit word per labelReliance Proprietary and Confidential
  21. 21. QoS in MPLS Network (cont…) DSCP & MPLS EXP Bits – DSCP field is not directly visible to MPLS Label Switch Routers (except edge LSR) – Information on DiffServ must be made visible to LSR in MPLS Header (using EXP field / Label)Reliance Proprietary and Confidential
  22. 22. Agenda What is QoS? Why QoS? Benefits of QoS For Service Provider QoS Functional Components & Models QoS in MPLS Network QoS Deployment ExperiencesReliance Proprietary and Confidential
  23. 23. QoS Deployment Experiences QoS deployment in MPLS network • Step 1: Identifying application requirements • Step 2: Defining Policies • Step 3: Testing policies • Step 4: Implementing policies • Step 5: Monitoring & adjustingReliance Proprietary and Confidential
  24. 24. QoS Deployment Experiences (Cont….) Step 1: Identifying Application Requirements • Importance of an application to the customer – What applications are considered “mission critical”? • Derived from application properties – Application performance/quality requirements – Properties of the underlying transport protocol stack • Applications with different properties/requirements should be queued separately • Interaction of SP’s (Service Provider) business team with various enterprise customers (for understanding various service classes profiles in finalizing QoS products)Reliance Proprietary and Confidential
  25. 25. QoS Deployment Experiences (Cont….) Step 1: Identify Application Requirements (cont..) - QoS Requirements of Applications example: Bandwidth Delay Jitter Loss Voice Payload Low Low Low Low Video Payload - Interactive (2-Way) High Low Low Low Video Payload - Streaming (1-Way) High High High Low Video Signaling Low Low Medium Medium Voice Signaling Low Low Medium Medium Data: Interactive,Mission Variable,typical Critical medium Medium Medium Medium Data: Not Interactive,Mission Variable,typically Critical high High High Medium Data: Interactive,Not Variable,typical Critical medium High High Medium Data: Not Variable,typically Interactive,Not Critical high High High HighReliance Proprietary and Confidential
  26. 26. QoS Deployment Experiences (Cont….) Step 2: Defining Policies • Understanding network topology and traffic flow • Assessing capacity of network devices (CPU, software, hardware etc.) and network links (speeds, overhead, congestion, etc.) • Identifying bottleneck and non-bottleneck links • Trusted and untrusted sources for QoS markings • Layer 2 vs. Layer 3 service model • Study & Research by SP’s business team to design QoS product profiles (Interactions with various enterprise customers to understand their business applications priorities) • Co-ordination among SP’s business team & technical team till the completion of QoS deploymentReliance Proprietary and Confidential
  27. 27. QoS Deployment Experiences (Cont….) Step 2: Defining Policies (cont….) – • Defining SP’s aggregate service class model (Keep minimum number of classes) • Mapping of customer’s service class model to SP’s one • Internet traffic is to be classified as Best Effort • Defining SLA for customer service classes • QoS mechanisms to be implemented at network edge & core • QoS Transparency with MPLS DiffServ Tunneling Modes (Handing of customer’s IPP/DSCP bits settings)Reliance Proprietary and Confidential
  28. 28. QoS Deployment Experiences (Cont….) Step 2: Defining Policies (cont….) – Example: QoS Standard Classification and Marking Rule Recommendations L3 Classification L2 CoS/MPLS EXP Application IPP PHB DSCP Routing 6 CS6 48 6 Voice 5 EF 46 5 Interactive-Video 4 AF41 34 4 Streaming Video 4 CS4 32 4 Mission-Critical Data 3 — 25 3 Call Signaling 3 AF31/CS3 26/24 3 Transactional Data 2 AF21 18 2 Network Management 2 CS2 16 2 Bulk Data 1 AF11 10 1 Scavenger 1 CS1 8 1 Best Effort 0 0 0 0Reliance Proprietary and Confidential
  29. 29. QoS Deployment Experiences (Cont….) Step 3: Testing Policies • QoS policies function of customer requirement (provided by SP’s business team) & SP’s n/w’s scalability, functionality • Test QoS policies in the lab first Testing feasibility of QoS product profiles provided by business team Testing these profiles under simulation of customer’s application traffic entering the SP’s n/w stochastically (under L2/L3 MPLS VPN scenario)Reliance Proprietary and Confidential
  30. 30. QoS Deployment Experiences (Cont….) Step 3: Testing Policies (cont….) • Test QoS policies in the lab first (cont….) Testing SP’s vendors QoS implementation for it’s routers’/switches’ hardware/software (currently functional in SP’s n/w) under different L2 encapsulations/markings & L3 protocol (IP)/markings Testing SP’s vendor’s n/w OS for whether classification & marking rules are obeyed under default as well as user-defined conditions or not as well as scheduling tools are functioning as expected or notReliance Proprietary and Confidential
  31. 31. QoS Deployment Experiences (Cont….) Step 3: Testing Policies (cont….) • Test QoS policies in the lab first (cont….) Testing of QoS service profiles’ actual behavior vs. exhibited behavior (both should match) Testing of QoS profiles for whether there is flexibility in allocation of n/w resources among different service classes Testing of SLA probing feature available in routers’/switches’ software for SLA monitoring & Capacity Planning purposeReliance Proprietary and Confidential
  32. 32. QoS Deployment Experiences (Cont….) Step 3: Testing Policies (cont….) • Test QoS policies in the lab first (cont….) Testing integration of this SLA probing feature with SP’s current NMS/OSS Test policy in a small portion of the production network Run baseline tests with and without QoS under congestion conditionsReliance Proprietary and Confidential
  33. 33. QoS Deployment Experiences (Cont….) Step 4: Implementing Policies • Perform Classification on MPLS PE routers • Perform policing and marking on MPLS PE routers • Work toward core applying inbound/outbound policies • Phased deployment—apply your policies incrementallyReliance Proprietary and Confidential
  34. 34. QoS Deployment Experiences (Cont….) Step 5: Monitoring and Adjusting • Measure delay and loss for different service classes • Monitor application performance • Adjust policies where necessaryReliance Proprietary and Confidential
  35. 35. Thank YouReliance Proprietary and Confidential

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